When Ben Ryan’s son Sol was born, Sol's left arm had to be removed due to birth complications. This father, realizing that many kids don’t get prosthetics until they’re teens, knew he had to do something to help encourage mobility. With no experience in the least, he set out to teach himself engineering, and in less than a couple years was already making 3-D printed prototypes. Incredibly, this self-taught engineer has made his son multiple prosthetics, and is now making them for kids in need all around the world.